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Parastomal hernia repair

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Plastic and Aesthetic Research 2022年第1期9卷 402-412页

作者： Jeffrey Michael Smith Sahil K.Kapur alexander f.Mericli Donald P.Baumann Charles E.Butler Department of Plastic Surgery The University of Texas MD Anderson Cancer CenterHoustonTX 77030USA Department of Surgery Division of Plastic SurgeryThe University of Texas Medical BranchGalvestonTX 77555USA

Despite significant advances in abdominal wall reconstruction,parastomal hernias remain a complex problem,with a high risk of recurrence following *** a number of surgical hernia repair techniques have been proposed,there is no consensus on optimal *** clinical variables must be considered when developing a comprehensive repair plan that minimizes the likelihood of hernia recurrence and surgical site *** this review,we describe the incidence of parastomal hernias and discuss pertinent risk factors,medical history findings,physical examination findings,supplementary diagnostic modalities,parastomal hernia classification systems,surgical indications,and repair *** consideration is given to the discussion of mesh reinforcement,including available biomaterials,anatomic plane selection,and the extent of mesh *** open repairs are the primary focus of this article,minimally invasive laparoscopic and robotic approaches are also briefly *** is our hope that the provided surgical outcome data will help guide surgical management and optimize outcomes for affected patients.

关键词： Abdominal wall reconstruction parastomal hernia stoma biologic mesh synthetic mesh polypropylene acellular dermal matrix

Characterization of Amino Acid Based Molecular Micelles with Molecular Modeling

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Open Journal of Physical Chemistry 2019年第4期9卷 221-240页

作者： alexander Billiot Yayin fang Kevin f. Morris Department of Physical and Environmental Sciences Texas A & M University-Corpus Christi Corpus Christi TX USA Department of Biochemistry and Molecular Biology College of Medicine Howard University Washington DC USA Department of Chemistry Carthage College Kenosha WI USA

The enantiomers of chiral drugs often have different potencies, toxicities, and biochemical properties. Therefore, the fDA and other worldwide regulatory agencies require manufactures to test and prove the enantiomeric purity of chiral drugs. Amino acid based molecular micelles (AABMM) have been used in chiral CE separations since the 1990’s because of their low environmental impact and because their properties can easily be tuned by changing the amino acids in the chiral surfactant head groups. Using molecular dynamics simulations to investigate the structures and properties of AABMM is part of an ongoing study focusing on investigating and elucidating the factors responsible for chiral recognition with AABMM. The results will be useful for the proper design and selection of more efficient chiral selectors. The micelles investigated contained approximately twenty covalently linked surfactant monomers. Each monomer was in turn composed of an undecyl hydrocarbon chain bound to a dipeptide headgroup containing of all combinations of L-Alanine, L-Valine, and L-Leucine. These materials are of interest because they are effective chiral selectors in capillary electrophoresis separations. Molecular dynamics simulation analyses were used to investigate how the sizes and positions of the headgroup amino acid R-groups affected the solvent accessible surface areas of each AABMM chiral center. In addition, headgroup dihedral angle analyses were used to investigate how amino acid R-group size and position affected the overall headgroup conformations. finally, distance measurements were used to study the structural and conformational flexibilities of each AABMM headgroup. All analyses were performed in the context of a broader study focused on developing structure-based predictive tools to identify the factors responsible for a) self-assembly, b) function, c) higher ordered structure and d) molecular recognition of these amino acid based molecular micelles.

关键词： Amino Acid Based Molecular Micelles Molecular Modeling Computational Chemistry

IL-6 prevents Th2 cell polarization by promoting SOCS3-dependent suppression of IL-2 signaling

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Cellular & Molecular Immunology 2023年第6期20卷 651-665页

作者： Holly Bachus Erin McLaughlin Crystal Lewis Amber M.Papillion Etty N.Benveniste Dave Durell Hill alexander f.Rosenberg AndréBallesteros-Tato Beatriz León Department of Medicine Division of Clinical Immunology and RheumatologyUniversity of Alabama at BirminghamBirminghamALUSA Department of Microbiology University of Alabama at BirminghamBirminghamALUSA Department of Cell Developmental and Integrative BiologyUniversity of Alabama at BirminghamBirminghamALUSA informatics Institute University of Alabama at BirminghamBirminghamALUSA Alexion Pharmaceuticals Inc.New HavenCTUSA

Defective interleukin-6 (IL-6) signaling has been associated with Th2 bias and elevated IgE levels. However, the underlying mechanism by which IL-6 prevents the development of Th2-driven diseases remains unknown. Using a model of house dust mite (HDM)-induced Th2 cell differentiation and allergic airway inflammation, we showed that IL-6 signaling in allergen-specific T cells was required to prevent Th2 cell differentiation and the subsequent IgE response and allergic inflammation. Th2 cell lineage commitment required strong sustained IL-2 signaling. We found that IL-6 turned off IL-2 signaling during early T-cell activation and thus inhibited Th2 priming. Mechanistically, IL-6-driven inhibition of IL-2 signaling in responding T cells was mediated by upregulation of Suppressor Of Cytokine Signaling 3 (SOCS3). This mechanism could be mimicked by pharmacological Janus Kinase-1 (JAK1) inhibition. Collectively, our results identify an unrecognized mechanism that prevents the development of unwanted Th2 cell responses and associated diseases and outline potential preventive interventions.

关键词： Th2 cell polarization IL-6 IL-2 SOCS3 JAK1 inhibitor

ASecond-Order finite-Difference Method for Compressible fluids in Domains with Moving Boundaries

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Communications in Computational Physics 2018年第1期23卷 230-263页

作者： Alina Chertock Armando Coco alexander Kurganov Giovanni Russo Department of Mathematics North Carolina State UniversityRaleighNC 27695USA Department of Mechanical Engineering and Mathematical Sciences Oxford Brookes UniversityOxford OX331HXUK Department of Mathematics Southern University of Science and TechnologyShenzhenGuangdong 518055China and Mathematics DepartmentTulane UniversityNew OrleansLA 70118USA Dipartimento diMatematica ed Informatica Universit`a di Catania95125CataniaItaly.

In this paper,we describe how to construct a finite-difference shockcapturing method for the numerical solution of the Euler equation of gas dynamics on arbitrary two-dimensional domainΩ,possibly with moving *** boundaries of the domain are assumed to be changing due to the movement of solid objects/obstacles/*** the motion of the boundary could be coupled with the fluid,all of the numerical tests are performed assuming that such a motion is prescribed and independent of the fluid *** method is based on discretizing the equation on a regular Cartesian grid in a rectangular domainΩ_(R)⊃Ω.Ωe identify inner and ghost *** inner points are the grid points located insideΩ,while the ghost points are the grid points that are outsideΩbut have at least one neighbor insideΩ.The evolution equations for inner points data are obtained from the discretization of the governing equation,while the data at the ghost points are obtained by a suitable extrapolation of the primitive variables(density,velocities and pressure).Particular care is devoted to a proper description of the boundary conditions for both fixed and time dependent *** numerical experiments are conducted to illustrate the validity of themethod.Ωe demonstrate that the second order of accuracy is numerically assessed on genuinely two-dimensional problems.

关键词： Compressible fluids Euler equations of gas dynamics ghost-cell extrapolation moving boundaries finite-difference shock-capturing methods

Impact of lattice relaxations on phase transitions in a high-entropy alloy studied by machine-learning potentials

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npj Computational Materials 2019年第1期5卷 670-676页

作者： Tatiana Kostiuchenko fritz Körmann Jörg Neugebauer alexander Shapeev Skolkovo Institute of Science and Technology Skolkovo Innovation CenterNobel St.3Moscow 143026Russia Computational Materials Design Max-Planck-Institut für Eisenforschung GmbH40237 DüsseldorfGermany Materials Science and Engineering Delft University of Technology2628 CD DelftThe Netherlands

Recently,high-entropy alloys(HEAs)have attracted wide attention due to their extraordinary materials properties.A main challenge in identifying new HEAs is the lack of efficient approaches for exploring their huge compositional *** initio calculations have emerged as a powerful approach that complements ***,for multicomponent alloys existing approaches suffer from the chemical complexity *** this work we propose a method for studying HEAs *** approach is based on the application of machine-learning potentials based on ab initio data in combination with Monte Carlo *** high efficiency and performance of the approach are demonstrated on the prototype bcc NbMoTaW *** approach is employed to study phase stability,phase transitions,and chemical short-range *** importance of including local relaxation effects is revealed:they significantly stabilize single-phase formation of bcc NbMoTaW down to room ***,a so-far unknown mechanism that drives chemical order due to atomic relaxation at ambient temperatures is discovered.

关键词： alloy relaxation entropy

Should antibiotics be administered before arthroscopic knee surgery? A systematic review of the literature

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World Journal of Orthopedics 2018年第11期9卷 262-270页

作者： John Carney Nathanael Heckmann Erik N Mayer Ram K Alluri Carleton Thomas Vangsness George f Hatch Ⅲ alexander E Weber Department of Orthopaedic Surgery University of Southern California

AIM To explore the current evidence surrounding the administration of prophylactic antibiotics for arthroscopic knee surgery. METHODS Databases were searched from inception through May of 2018 for studies examining prophylactic antibiotic use and efficacy in knee arthroscopy. Studies with patient data were further assessed for types of arthroscopic procedures performed,number of patients in the study,use of antibiotics,and outcomes with the intention of performing a pooled analysis. Data pertaining to "deep tissue infection" or "septic arthritis" were included in our analysis. Reported data on superficial infection were not included in our data analysis. for the pooled analysis,a relative risk ratio was calculated and χ~2 tests were used to assess for statistical significance between rates of infection amongst the various patient groups. Post hoc power analyses were performed to compute the statistical power obtained from our sample sizes. Number needed to treat analyses were performed for statistically significant differences by dividing 1 by the difference between the infection rates of the antibiotic and no antibiotic groups. An alpha value of 0.05 was used for our analysis. Study heterogeneity was assessed by Cochrane's Q test as well as calculation of the I^2 *** A total of 49682 patients who underwent knee ar-throscopy for a diverse set of procedures across 19 studies met inclusion critera for pooled analysis. for those not undergoing graft procedures,there were 27 cases of post-operative septic arthritis in 34487 patients(0.08%) who received prophylactic antibiotics and 16 cases in 10911(0.15%) who received none [risk ratio(RR) = 0.53,95% confidence interval(CI): 0.29-0.99,P = 0.05]. A sub-group analysis in which bony procedures were excluded was performed which found no significant difference in infection rates between patients that received prophylactic antibiotics and patients that did not(P > 0.05). All anterior cruciate ligament reconstruction

关键词： Knee arthroscopy Antibiotics Systematic review Vancomycin Anterior cruciate ligament

The stadium effect:rodent damage patterns in rice fields explored using giving-up densities

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Integrative Zoology 2017年第6期12卷 438-445页

作者： Clare R.JONES Renee P.LORICA James M.VILLEGAS Angelee f.RAMAL finbarr G.HORGAN Grant R.SINGLETON alexander M.STUART Crop and Environmental Sciences Division International Rice Research InstituteMetro ManilaPhilippines Natural Resources Institute University of GreenwichChatham MaritimeKentUK Centre for Compassionate Conservation University of Technology SydneyNew South WalesAustralia

Rodents are globally important pre-harvest pests of *** Southeast Asia,rodent damage to growing rice crops is commonly concentrated towards the center of rice fields,away from the field edge,resulting in a clear pattern known as the“stadium effect.”To further understand this behavior of rodent pests and to develop recommendations for future research and management,we examined the relation between giving-up densities(GUDs)and damage *** Tanay,Luzon,Philippines,GUD trays containing pieces of coconut in a matrix of sand were placed at 4 different distances from the field edge to quantify the perceived risk of predation in a rice field pest,Rattus *** were recorded during a dry and wet season crop at the reproductive and ripening stages of *** addition,assessments of active burrows,tracking tile activity and rodent damage to the rice crop,were conducted in the dry *** were significantly lower in the center of the rice fields than on the field edges,suggesting that rodent damage to rice is greater in the middle of rice fields due to a lower perceived predation ***,this perception of predation risk(or fear)increases towards the field edge and was greatest on the rice bund,where there was no vegetation *** discuss the implications for rodent management and rodent damage assessments in rice *** is the first documented use of GUDs in a rice agro-ecosystem in Asia;thus we identify the challenges and lessons learned through this process.

关键词： habitat use landscape of fear pest management Rattus tanezumi rodent behavior

Effect of electron injection in copper-contacted graphene nanoribbons

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Nano Research 2016年第9期9卷 2735-2746页

作者： Konstantin A.Simonov Nikolay A.Vinogradov alexander S.Vinogradov alexander V.Generalov Gleb I.Svirskiy Attilio A.Cafolla Nils Martensson Alexei B. Preobrajenski Department of Physics and Astronomy Uppsala UniversityUppsala Box 51675120Sweden MAX Ⅳ Laboratory Lund UniversityLund Box 11822100Sweden V.A.fock Institute of Physics St.Petersburg State UniversitySt.Petersburg 198504Russia School of Physical Sciences Dublin City UniversityDublin 9Ireland

for practical electronic device applications of graphene nanoribbons (GNRs), it is essential to have abrupt and well-defined contacts between the ribbon and the adjacent metal lead. By analogy with graphene, these contacts can induce electron or hole doping, which may significantly affect the I/V characteristics of the device. Cu is among the most popular metals of choice for contact materials. In this study, we investigate the effect of in situ intercalation of Cu on the electronic structure of atomically precise, spatially aligned armchair GNRs of width N = 7 (7-AGNRs) fabricated via a bottom-up method on the Au(788) surface. Scanning tunneling microscopy data reveal that the complete intercalation of about one monolayer of Cu under 7-AGNRs can be facilitated by gentle annealing of the sample at 80 °C. Angle-resolved photoemission spectroscopy (ARPES) data clearly reflect the one-dimensional character of the 7-AGNR band dispersion before and after intercalation. Moreover, ARPES and core-level photoemission results show that intercalation of Cu leads to significant electron injection into the nanoribbons, which causes a pronounced downshift of the valence and conduction bands of the GNR with respect to the fermi energy (ΔE ~ 0.5 eV). As demonstrated by ARPES and X-ray absorption spectroscopy measurements, the effect of Cu intercalation is restricted to n-doping only, without considerable modification of the band structure of the GNRs. Post-annealing of the 7-AGNRs/Cu/Au(788) system at 200 °C activates the diffusion of Cu into Au and the formation of a Cu-rich surface Au layer. Alloying of intercalated Cu leads to the recovery of the initial position of GNR-related bands with respect to the fermi energy (E f), thus, proving the tunability of the induced n-doping.

关键词： graphene nanoribbons bottom-up method copper intercalation charge injection angle-resolved photoemission spectroscopy (ARPES) scanning tunneling microscopy

A new look at the first dinosaur discovered in Antarctica:reappraisal of Antarctopelta oliveroi(Ankylosauria:Parankylosauria)

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Advances in Polar Science 2024年第1期35卷 78-107页

作者： Sergio SOTO ACUÑA alexander OVARGAS Jonatan KALUZA Red Paleontológica U-Chile Departamento de BiologíaFacultad de CienciasUniversidad de ChileÑuñoa 7800003Chile Escuela de Geología Facultad de CienciasIngeniería y TecnologíaUniversidad MayorProvidenciaSantiago 7500994Chile fundación de Historia Natural félix de Azara Universidad MaimónidesBuenos Aires C1405Argentina Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET) Buenos Aires C1425FQBArgentina

The first dinosaur discovered in the Antarctic continent was the ankylosaur Antarctopelta oliveroi in the ***,since then several hypotheses of phylogenetical relationships have been proposed because these have been depended on how the skeletal remains have been *** main obstacle for clarifying its phylogenetic position is that many portions of the skeleton remain unknown,in addition to the presence of unknown characters in typical *** an ankylosaurid,nodosaurid,or even a chimaera,a recent proposal based on mostly complete material of a new ankylosaur from Chilean Patagonia provided support for a novel phylogenetic hypothesis:Antarctopelta and other southern ankylosaurs are an early branching clade,the Parankylosauria,whose origin probably dates to the Late *** the light of this new view,a redescription of the available skeletal remains is provided together with a new reconstruction of the first Antarctic dinosaur known to the science community.

关键词： Antarctic Peninsula Biogeographic Weddellian Province Parankylosauria Antarctopelta